Smartly designed tin oxide nanoparticles with synergistic effect of a ball milling and composite temperature towards high efficiency planar perovskite solar cells (Conference Presentation)

Metal oxide transporting layer in organic-inorganic perovskite solar cells (PSCs) have a tremendous improvement in both aspects, first stability and second high power conversion efficiency (PCE) which provides a new platform for commercialization in near future. Herein we report for the first time a novel home-made ball milling technique for the synthesis of tin oxide (SnO2) nanoparticles (10~20 nm sizes) fabricated at composite temperature, employed as an electron transporting layer (ETL) in planar PSCs. A smartly designed ground SnO2 (G-SnO2) NPs which annealed at high temperature (≤ 300°C) and an additional layer of a SnO2 layer (C-SnO2) which converted from the precursor (SnCl2.2H2O), annealed at low temperature (≤ 200°C). This synergistic effect gives a pinhole-free layer of G-SnO2 NPs, which helps to improve the bonding and interlayer recombination between ETL and absorber layer. We fabricated C-SnO2, G-SnO2, and G-SnO2/C-SnO2 based PSCs, with champion PCE of 16.4%, 17.9% and 19.11% respectively, with an active area of 0.04 cm2. The G-SnO2 and G-SnO2/C-SnO2 based devices have long-term stability and less hysteresis compare to C-SnO2 based device.